Re: QDX rev 5 Troubleshooting
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Hi all, trying to workout why my QDX isn't transmitting on 20m & 30m. Built the QDX a few weeks ago, and have many QSOs on 40m and some on 80m. I can receive on all band but transmit on 20 shows no power out, with the LED doing the slow flash transmit as per 40m and 80m.
I’ve checked the continuity on all of the coils to the next component, so the enamel is cleaned of and the wire soldered to the trace, although I had to add a bodge wire for one of the T1 connections! And I’ve generally inspected and re-flowed anything looking suspect, everything
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Trawled the group and came across the diode test, below are my outputs using an oscilloscope. The outputs marked with “Vpp” show the voltage peak to peak, whereas the “V” are DC.
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Any ideas on what to check next?
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Diode
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80 Vpp
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40 Vpp
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20Vpp
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D1
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5.6 Vpp
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5.13 V
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5.13 V
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D2
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5.13 V
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6 Vpp
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5.13 V
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D3
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5.13 V
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5.13 V
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145mVpp
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D4
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6.18 Vpp
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5.13 V
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5.13 V
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D5
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5.13 V
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6.18 Vpp
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5.13 V
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D6
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5.13 V
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5.13 V
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1.8mVpp
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